The present invention relates to electrical circuits designed to protect appliances from the effects of lightning. More specifically, the invention relates to a circuit which serves to isolate the components of a television set, or the like, from the electrical path of lightning through operation of the set's on-off switch.
It is a well-known fact that certain electrical household appliances are subject to damage from the effects of the extremely high voltage loads which are present when lightning from an electrical storm passes through the appliance. For example, radio receivers and television sets which are commonly plugged into the household electrical supply, and may also be connected to outside antennae are particularly susceptible to damage by lightning of components which may be quite expensive to replace. In conventional sets, one side of the AC power line remains connected through components of the set to the chassis when the set is turned off, providing a path for lightning from the AC line to the antenna ground. Although the appliance may be protected by disconnecting the electrical supply and antenna connections, this is often impractical or inconvenient.
A principal object of the present invention is to provide circuit means for incorporation in or with a standard television set, or similar electrical appliance, which will substantially insure against lightning damage when the set is turned off.
Another object is to provide a simple and economical circuit attachment for standard FM or AM radio receivers, television sets, etc., which protects the components from damage by lightning without the necessity of unplugging the set and disconnecting the antenna during electrical storms.
Other objects will in part be obvious and will in part appear hereinafter.